All appointments disappeared from calendar

Today someone called me and i missed the call. However the number remained on my outside screen when the phoned was closed so i did a battery pull.

When the phone came back on it mentioned something about a certificate expiring or not being verified so i closed the connection, since i could not figure out what it was for. Then I noticed a few things wrong 1) all my text messages were gone, 2) all my hotmail emails were gone, 3) the BB thought it was march 2013 and most important 4) all my calendar appointments are gone.

I did another battery pull after to see if that fixed it but when it starts up again it does not mention the certificate or anything else and the BB again thinks its march 2013.

Someone have any idea what i did and how to fix it?

The same thing happened to me today, except I believe it happened after I uninstalled Facebook. Every calendar entry disappeared. Just before that, the BB got "hung up" twice and I had to remove the battery each time. Now it seems to work fine, but no calendar entries and the "default" calendar has changed to Desktop instead of my email address. I've had blackberries for 6 years and this has never happened!